@Override
void accum(Context ctx, float value) {
if (VERBOSE) System.err.println("JoglPipeline.accum()");
GL2 gl = context(ctx).getGL().getGL2();
gl.glReadBuffer(GL.GL_BACK);
gl.glAccum(GL2.GL_ACCUM, value);
gl.glReadBuffer(GL.GL_FRONT);
}
// This is the native method for doing accumulation return.